1. Field of the Invention
The present invention relates to an image display apparatus having a communication function.
2. Background
One conventional image display apparatus is disclosed in the Japanese Laid Open Patent Specification Sho 63(1988)-18384, which corresponds to the U.S. Pat. No. 4,788,564, issued Nov. 29, 1988.
This conventional display apparatus is explained briefly as follows, referring to FIG. 5.
This apparatus 108 has a display belt 109, on which an image is formed, which is endless and whose surface is white. The display belt 109 is supported by a pair of rollers 110 and 111 disposed vertically such that the belt 109 is able to move parallel to a display part 112. An image forming part 113 is also provided to form images on the belt 109 electrostatically with conductive magnetic toner by using a method, for example, as disclosed in U.S. Pat. No. 3,194,771, which discloses how to form an image with conductive magnetic toner. The magnetic toner T is transported to a recording electrode 116 on a surface of a non magnetic cylinder 115 in response to rotation of a rotating magnet 114. The recording electrode 116 is driven by a driving device 118 driven in turn by a display image signal from an image input device 117. When the driving device 118 applies a predetermined voltage, then the magnetic toner T is attached to the display belt 109 and thereby the image is formed.
The above-mentioned image display apparatus is operated by an operator who supplies image data to be displayed by controlling an image reader, a personal computer, or the like. Therefore, an operator must be near by the display apparatus.
The present inventors have considered how an operator can send image data via a facsimile communication line from a distant place to the display apparatus to display image data. Such a facsimile apparatus is disclosed in Japanese Laid Open Publication Sho54 (1979)-53915. An operator, however, who has sent image data in this way cannot confirm which image data is displayed, nor discriminate whether displayed image data should be erased or replaced or not.
Therefore, it is preferable that a distant operator be able to recognize which image is displayed on the display apparatus without a special apparatus.
Further, in the case where the apparatus can display an image from a distant station by using any method, any of the operators can change the displayed image innocently or mischievously unless the operator is limited. Therefore, it is preferable to avoid such mischief.
In the case where an operator wants to change an image to be displayed, it is also a problem if the operator has to order from the remote location every time.